Vent for soil pipe stack

ABSTRACT

A soil pipe vent stack having a cartridge-type filter telescopically arranged within the open upper end thereof, the filter being adapted to control the emission of obnoxious gases from the vent stack.

United States Patent 1151 3,638,402 Thomas Feb. 1, 1972 VENT FOR SOILPIPE STACK References Cited [72] Inventor: Clarence II. Thomas, [8240Sycamore UNITED STATES PATENTS 1,838,737 12/1931 Boynton et al ..55/325[22] Filed: June 2, 1970 1,771,639 7/1930 Jordahl ..55/486 x 1,459,6106/1923 Bosshart et al. ..55/486 3,220,079 11/1965 Aggson ..98/1 18 x2,472,383 6/1949 Owens ..55/38.5 x 52 us. Cl ..5s/307, 4/219, 21/53,154,645 9/1874 Chase ..55/387 x 21/55, 21/74, 55/310, 55/325, 55/385,55/442, 55/489, 55/494, 55/504, 55/507, 55/509, 55/513, PrimaryExaminer-Dennis E. Ta1bert,.lr.

' 55/525, 55/529, 98/122 Assistant Examiner-Vincent Gifl'ord [51] Int.Cl. ..E03f 5/08 AnarneyBames, Kisselle, Raisch & Choate [58] FieldolSearch ..55/279, 307, 308, 315, 316,

ABSTRACT A soil pipe vent stack having a cartridge-type filtertelescopically arranged within the open upper end thereof, the filterbeing adapted to control the emission of obnoxious gases from the ventstack.

15 Claims, 3 Drawing Figures PATENTED FEB 1 m2.

INVENTOR. CLARENCE H. THoMAs ATTORNEVS VENT FOR SOIL PIPE STACK Thisinvention relates to soil pipe vents and more particularly to a filterdevice for reducing the discharge of obnoxious odors from soil pipe ventstacks.

Sanitary drains, soil pipes, etc., which carry human wastes fromresidential and other buildings are normally vented by means of a stackextending upwardly from the sanitary drain line to above the roof of thebuilding. The gases developed in these drains are normally very humidand laden with obnoxious odors, presumably caused by bacteria, germsandthe like. These gases are normally heavier than air and, when dischargedfrom the upper open end of the vent stack by reason of the gaseouspressure developed in the sanitary drain, they tend to settle nearground level, thus not only producing obnoxious odors but also pollutingthe air with potentially harmful germs and bacteria.

The present invention has for its object the provision of a filteradapted to be mounted at the open upper end of the vent stack of a soilpipe which tends to remove moisture, germs and obnoxious odors from thegases emitted from such vents.

Other features and objects of the invention will become apparent fromthe accompanying description and drawing, in which:

FIG. I is a fragmentary view of a building provided witha vent stackfrom a sanitary drain provided with the filter of the present invention.

FIG. 2 is a sectional view along the line 2-2 in FIG. 1.

FIG. 3 is asectional view along the line 3-3 in FIG. 2.

In the drawing there is shown a residential building structure generallydesignated and provided with a roof 12. A vent stack 14 extendsvertically upwardly in the building structure from the soil pipe orsanitary drain system in the building (not illustrated) through roof 12with its open upper end 16 projecting above roof 12. The gasescollecting or developed in the sanitary drain system are adapted to bevented to the outside atmosphere through stack 14.

The filter of the present invention is generally designated 18 andcomprises a cylindrical open ended casing 20 having a diameter slightlyless than the diameter of the open upper end 16 of stack 14. Around itsupper end casing 20 is provided with a radially outwardly extendingperipheral flange 22 by means of which casing 20 is supported within theopen upper end 16 of stack 14. Flange 22 also seals the annular spacebetween stack l4 and casing 20. A plurality of spring clips 24 aresecured to flange 22 and are adapted to frictionally engage the outersurface of stack 14 for retaining the filter 18 in positron.

Within casing 20 there are arranged two sets of baffles 26 and 28.Baffle 26 extends transversely across the interior of casing 20 adjacentthe lower end thereof and comprises a plurality of regularly spacedvanes 30 which are inclined to the vertical in one direction. Thus, thegases passing upwardly through baffle 26 are deflected by vanes 30 inthe manner indicated by arrows 32. Upper baffle 28 is locatedapproximately midway between the upper and lower ends of casing 20 and,like baffle 26, comprises a series of regularly spaced vanes 34.However, vanes 34 are inclined in a direction opposite to theinclination of vanes 30 and the gases passing upwardly therethrough arethus deflected as indicated by arrows 36. In view of the oppositeinclination of the vertically spaced vanes 30,34, the gases flowingupwardly through casing 20 are caused to follow a circuitous path.

Directly above upper baffle 28 there is arranged within casing 20 acylindrical tube or casing 38 which is concentric to casing 20. Casing38 is supported at its lower end on casing 20 by three radiallyextending support arms 40, Casing 38 is open at its upper and lower endsand its diameter is substantially smaller than the inner diameter ofcasing 20. Preferably casing 38 has a diameter not greater than aboutone-third the diameter of casing 20 so that the cross-sectional area ofcasing 38 is relatively small in comparison with the cross-sectionalarea of casing 20.

The space between casings 20 and 38 above baffle 28 is defined by anannular chamber 42. Chamber 42 is filled with a filtering medium 44,preferably a metal wool such as a copper mesh material. The use of acopper mesh material in the nature of a metal wool is preferablyemployed as the filtering medium because of its ability to resistatmospheric corrosion and because of its apparent filtering qualitieswith respect to the gases discharged from stack I4.

Although the reasons therefor are not absolutely certain, in operationfilter I8 prevents the obnoxious odors normally discharged from a ventstack from settling at ground level. This may be due to the fact thatthe combination of baffles 26 and 28 in conjunction with the filteringmedium 44 has a tendency to condense the moisture vapor contained in thegases flowing upwardly through the vent stack. The condensation'of suchmoisture vapor is evidenced by the corrosion accumulating on baffles26,28 after the filter has been in use for a period of time. It ispossible that this condensation effect tends to trap a great portion ofthe matter imparting a foul odor to the gases. It is also probable thatthe condensation resulting'from the provision of baffles 26,28 incombination with the filtering medium 44 reduces the specific gravity ofthe gases being discharged from the vent to such an extent that they donot descend after leaving the upper open end of the stack. In any event,experience has shown that when the filter disclosed herein is employedat the upper end of a vent stack as shown the obnoxious odors normallyassociated with such vented gases are substantially completelyeliminated.

The use of the open ended central casing or tube 38 has been found to bedesirable in order to prevent a buildup of back pressure in the sanitarydrain system. However, the amount of gases escaping directly upwardlythrough casing 38 is relatively small in comparison to the total volumeof gases being vented so that a major portion of the gas is caused toflow through the filtering medium 44 and the central casing 38 merelyserves as a relief valve to prevent substantial back pressure in thesanitary drain system.

Iclaim:

I. A filter for a soil pipe vent stack comprising an open endedcylindrical casing adapted to be mounted at the open upper end of a soilpipe vent stack so that the gases escaping from the vent stack arecaused to flow upwardly through said casing, said casing having at leasttwo sets of vertically spaced baffles therein, each set of said bafflesextending substantially entirely across the cross section of saidcylindrical casing and comprising a plurality of spaced apart vanesinclined to the vertical axis of the casing, the uppermost set of saidbaffles being located substantially below the upper end of said casingand defining the lower end of a cylindrical chamber at the upper end ofsaid casing and a gas filtering medium in said cylindrical chamber.

2. A filter as called for in claim 1 including a second open endedcylindrical casing disposed concentrically within said cylindricalchamber, Said filter medium being disposed between said first and secondcasings and substantially filling the space therebetween.

3. A filter as called for in claim 2 wherein the cross-sectional area ofthe second cylindrical casing is relatively small in comparison with thecross-sectional area of the first cylindrical casing.

4. A filter as called for in claim 3 wherein said filter mediumcomprises a metal woollike material.

5. A filter as called for in claim 3 wherein the diameter of said secondcasing is not greater than about one-third the diameter of said firstcasing.

6. A filter as called for in claim 5 wherein said second casing extendsfrom the upper set of baffles to adjacent the upper end of the firstcasing.

7. A filter as called for in claim 6 wherein said second casing has alength equal to about one-halfthe length of said first casmg.

8. A filter as called for in claim 3 wherein said first casing isprovided with a radially outwardly extending peripheral flange aroundthe upper end thereof, said flange being adapted to engage the upper endof the vent stack when the filter is inserted therein to thereby supportthe filter within the open upper end of the vent stack.

9. A filter as called for in claim 8 including a plurality of springclips on said peripheral flange for frictionally engaging the upper endof the vent stack.

10. In combination, a soil pipe vent stack having a vertically extendingopen upper end, a filter connected to said open upper end such that thegases emitted from said vent stack are constrained to flow through saidfilter, said filter comprising an open ended cylindrical casing havingat least two sets of vertically spaced baffles therein, each set of saidbaffles extending substantially entirely across the cross section ofsaid cylindrical casing and comprising a plurality of spaced apartinclined to the vertical axis of the casing, the uppermost set of saidbaffles being located substantially below the upper end of said casingand defining the lower end of a cylindrical chamber at the upper end ofsaid casing and a gas filtering medium in said cylindrical chamber.

11. The combination called for in claim 10 wherein said cylindricalcasing is telescopically arranged within said open upper end of the ventstack and including means at the upper end of the filter for supportingthe filter at said open upper end of the filter stack.

12. The combination called for in claim ll wherein said last-mentionedmeans comprises a radially outwardly extending peripheral flange aroundsaid cylindrical casing, said peripheral flange having an outer diametergreater than the outer diameter of the vent stack so as to support thefilter on the' vent stack and to seal the space between the outerperiphery of said casing and the inner periphery of the vent stack.

13. The combination called for in claim 12 including a second open endedcylindrical casing disposed concentrically within said cylindricalchamber. said filtcr medium being disposed between said first and secondcasing and substantially filling the space therebetween.

14. The combination called for in claim 13 wherein said filtering mediumcomprises a metal woollike material.

15. The combination called for in claim 14 wherein the diameter of saidsecond casing is not greater than about one third the diameter of saidfirst casing.

22 3 UNITED STATES PATENT OFFICE CETIFICATE OF CORRECTION Patent No. 2Dated Februarv 1. 1972 Inventor(s) THOMAS, nce H.

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 3, Line 15 After "apart" insert vanes Signed and sealed this 20thday of June 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents

1. A filter for a soil pipe vent stack comprising an open endedcylindrical casing adapted to be mounted at the open upper end of a soilpipe vent stack so that the gases escaping from the vent stack arecaused to flow upwardly through said casing, said casing having at leasttwo sets of vertically spaced baffles therein, each set of said bafflesextending substantially entirely across the cross section of saidcylindrical casing and comprising a plurality of spaced apart vanesinclined to the vertical axis of the casing, the uppermost set of saidbaffles being located substantially below the upper end of said casingand defining the lower end Of a cylindrical chamber at the upper end ofsaid casing and a gas filtering medium in said cylindrical chamber.
 2. Afilter as called for in claim 1 including a second open endedcylindrical casing disposed concentrically within said cylindricalchamber, said filter medium being disposed between said first and secondcasings and substantially filling the space therebetween.
 3. A filter ascalled for in claim 2 wherein the cross-sectional area of the secondcylindrical casing is relatively small in comparison with thecross-sectional area of the first cylindrical casing.
 4. A filter ascalled for in claim 3 wherein said filter medium comprises a metalwoollike material.
 5. A filter as called for in claim 3 wherein thediameter of said second casing is not greater than about one-third thediameter of said first casing.
 6. A filter as called for in claim 5wherein said second casing extends from the upper set of baffles toadjacent the upper end of the first casing.
 7. A filter as called for inclaim 6 wherein said second casing has a length equal to about one-halfthe length of said first casing.
 8. A filter as called for in claim 3wherein said first casing is provided with a radially outwardlyextending peripheral flange around the upper end thereof, said flangebeing adapted to engage the upper end of the vent stack when the filteris inserted therein to thereby support the filter within the open upperend of the vent stack.
 9. A filter as called for in claim 8 including aplurality of spring clips on said peripheral flange for frictionallyengaging the upper end of the vent stack.
 10. In combination, a soilpipe vent stack having a vertically extending open upper end, a filterconnected to said open upper end such that the gases emitted from saidvent stack are constrained to flow through said filter, said filtercomprising an open ended cylindrical casing having at least two sets ofvertically spaced baffles therein, each set of said baffles extendingsubstantially entirely across the cross section of said cylindricalcasing and comprising a plurality of spaced apart inclined to thevertical axis of the casing, the uppermost set of said baffles beinglocated substantially below the upper end of said casing and definingthe lower end of a cylindrical chamber at the upper end of said casingand a gas filtering medium in said cylindrical chamber.
 11. Thecombination called for in claim 10 wherein said cylindrical casing istelescopically arranged within said open upper end of the vent stack andincluding means at the upper end of the filter for supporting the filterat said open upper end of the filter stack.
 12. The combination calledfor in claim 11 wherein said last-mentioned means comprises a radiallyoutwardly extending peripheral flange around said cylindrical casing,said peripheral flange having an outer diameter greater than the outerdiameter of the vent stack so as to support the filter on the vent stackand to seal the space between the outer periphery of said casing and theinner periphery of the vent stack.
 13. The combination called for inclaim 12 including a second open ended cylindrical casing disposedconcentrically within said cylindrical chamber, said filter medium beingdisposed between said first and second casing and substantially fillingthe space therebetween.
 14. The combination called for in claim 13wherein said filtering medium comprises a metal woollike material. 15.The combination called for in claim 14 wherein the diameter of saidsecond casing is not greater than about one-third the diameter of saidfirst casing.